The present invention relates to a paper feeder for a printer having a paper feed sprocket, and more particularly to a paper feeder having a paper holder which can be opened in order to engage a printing paper web with the feed sprocket. There are two kinds of paper feed methods, one of which is a paper web pushing method and the other is a paper web drawing method. The present invention is concerned with a paper feeder to feed a paper web by the pushing method.
FIG. 4 shows a conventional paper feeder for a printer. The paper feeder is disposed behind a platen 1 and comprises a pair of sprockets 5 and a paper holder 4 provided on each sprocket. The sprockets 5 are disposed at both ends of a printing paper web 2, and the paper holder is rotatably attached to a case (not shown) for the sprocket. A paper guide 3 is disposed under the platen 1 to guide the outer surface of the paper 2 fed by the paper feeder. A print head 6 is disposed adjacent to the platen 1. Thus, when the sprocket wheels 5 are rotated by a drive mechanism (not shown), the paper 2 is fed to the platen 1.
In such a device, in order to set the paper web, the paper holder 4 is opened as shown by the chain line of FIG. 4. Therefore, the paper feeder must be arranged spaced away from the platen 1 so as to avoid the holder 4 from touching the platen 1. Thus, the paper feeder is disposed behind the platen 1 with a large space 7. In such a disposition, the paper web 2 fed to the platen 1 buckles or wrinkles into a convex portion 2a in the space 7, which causes mis-feeding of the paper web 2. Particularly, it occurs when a plurality of sheets of paper are fed, one over another.